Portion of an electronic mouse



FIG. 1 is a front perspective view of a portion of an electronic mouse showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a front view thereof; and,

FIG. 5 is a rear view thereof.

The broken line showing of various regions in the Figures and the unshaded areas therein is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of an electronic mouse, as shown and described. 